Many process streams exist that require advanced chemical treatment. These streams range from potable drinking water to industrial process streams. These industrial process streams contain a multitude of soluble compounds that require treatment by some process. This can include pretreatment before discharge into a publically owned treatment works (POTW). The soluble compounds include but are not limited to arsenic, nitrates, organics, compounds in potable water as well as a list of a multitude of compounds dissolved in industrial process waters. These contaminants and the variety of contaminants make the process streams difficult to treat with conventional techniques. Additionally, many process production streams require specialized equipment. A multitude of treatments and process systems have been designed to treat the various streams described above. These range from conventional chemical treatment processes to ion exchange to electro coagulation devices. These processes have been implemented in various streams with varying degrees of success. All processes additionally have inherent limitations.
The process that most closely resembles the disclosure described herein is a conventional electro-coagulation (EC) process. Conventional electro-coagulation is a physiochemical process that is produced by passing an electrical current through metallic plates immersed in an electrically conductive solution. The apparatus performing this process is termed an “EC apparatus.” This process has been described in multiple versions for more than 75 years. In conventional electro-coagulation, solutions are passed over plates of various metallic compounds. The metallic plates are energized by direct current (DC) voltage producing an electrified solution. It is implied herein that the solutions must be conductive. The voltage creates many physiochemical phenomena in the fluid passed between the plates. These range from strong magnetic forces, high reduction potentials (by the formation of radicals), ionized metal compounds and ionized hydroxide ions.
The manifestation of the electro-coagulation process is the formation of chemically generated floc that are produced from the metallic ions acting on the impurities (termed “particles” herein) in the solutions. Coagulation is brought about primarily by the reduction of the net surface charge to a point where the colloidal particles (impurities), previously stabilized by electrostatic repulsion, can approach closely enough for van der Waals forces to hold them together and allow aggregation. It has been described that the physiochemical reactions of the electro-coagulation process occur at the surface of the electrical plate. The floc provides a mechanism to bind to particles and allow the material to be removed from solution in the form of a solid or precipitant.
In all the previous versions of the electro-coagulation process, solutions are passed in a base laminar flow pattern over the electrical plates. In these variations, it is desired that the process steam have a defined contact time with the surface of the electrolytic cell, allowing the formation of the precipitant at the surface of the electrolytic cell. This requires that the cell has adequate surface area in order that the reaction can run to completion. All previous versions of the implementation of an electrical cell for process purposes described herein has relied on the flow patterns generated by the flow of a fluid over a cell of various configurations (inclined plates, liner plates, plates suspended in frames, etc). The previous implementations have many limitations. The criticality of surface contact has necessitated detailed fabrication requirements, size requirements, and spacing tolerances of the electrolytic cell, with resulting high scaling potentials on the surface of the plates, high heat generation, large surface area and large electrical loading.